System and method for encoding and decoding information signals using a priori information

Abstract

A system and method for coding and decoding an information signal sent through a communication system. The system includes: an encoder for encoding the information signal without adding additional information and for sending an encoded information signal; and a soft bit decoder including a-priori information related to the communication system for receiving the encoded information signal and decoding the encoded information signal using the a-priori information.

We claim: 
     
       1. A method for coding and decoding an information signal sent through a communication system comprising:
 preparing a-priori information related to the communication system; 
 receiving an information signal; 
 encoding the information signal at an encoder without adding additional information, wherein encoding the information signal without adding additional information comprises source coding without channel coding, wherein source coding comprises removing redundancies in the information signal; 
 sending the encoded information signal through a channel of the communication system; 
 receiving the encoded information signal at a soft bit decoder; 
 applying the a-priori information to the received encoded information signal to produce soft-bit probabilities; and 
 decoding the soft-bit probabilities. 
 
     
     
       2. The method of  claim 1 , wherein the a-priori information related to the communication system comprises a-priori knowledge related to one or more of the encoder, the channel, and a signal type of the information signal. 
     
     
       3. The method of  claim 1 , wherein the a-priori information comprises a probability distribution related to the encoder. 
     
     
       4. The method of  claim 3 , wherein the probability distribution comprises a table of probabilities. 
     
     
       5. The method of  claim 1 , wherein the encoding the information signal without adding additional information comprises encoding the information signal without forward error correction information. 
     
     
       6. The method of  claim 1 , wherein the decoding the soft-bit probabilities comprises selecting the most likely decoder output based on maximum a-posteriori probability. 
     
     
       7. The method of  claim 1 , wherein the decoding the soft-bit probabilities comprises selecting the most likely decoder output based on minimum mean square. 
     
     
       8. A system for coding and decoding an information signal sent through a communication system comprising:
 an encoder for encoding the information signal without adding additional information and for sending an encoded information signal, wherein encoding the information signal without adding additional information comprises performing source coding without channel coding, wherein the source coding comprises removing redundancies in the information signal; and 
 a soft bit decoder comprising a-priori information related to the communication system for receiving the encoded information signal and decoding the encoded information signal using the a-priori information; 
 wherein the soft bit decoder comprises an a-priori processor for applying the a-priori information to the received encoded information signal to produce soft-bit probabilities, and a source decoder for decoding the soft-bit probabilities. 
 
     
     
       9. The system of  claim 8 , wherein the a-priori information related to the communication system comprises a-priori knowledge related to one or more of the encoder, the channel, and a signal type of the information signal. 
     
     
       10. The system of  claim 8 , wherein the a-priori information comprises a probability distribution related to the encoder. 
     
     
       11. The system of  claim 10 , wherein the probability distribution comprises a table of probabilities. 
     
     
       12. The system of  claim 8 , wherein the encoder is arranged to encode the information signal without adding additional information by encoding the information signal without forward error correction information. 
     
     
       13. The system of  claim 8 , wherein the source decoder is arranged to decode the soft-bit probabilities by selecting the most likely decoder output based on maximum a-posteriori probability. 
     
     
       14. The system of  claim 8 , wherein the source decoder is arranged to decode the soft-bit probabilities by selecting the most likely decoder output based on minimum mean square.